Using an Atari ST as Unix/Linux Terminal

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Revision as of 18:12, 24 May 2012 by >Marcello
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According to Wikipedia, a text terminal is "a serial computer interface for text entry and display". It was the principal way of communicating with computers in the 70's. As a Text terminal requires extremely basic computing needs, it is easy to emulate in software, even on a 8 bit computer.

Text terminal.jpg

Basically when you have your ST configured as a Text terminal, you will get something very similar to a GNU/Linux xterm or gnome-terminal, except if will be using the keyboard and screen of your ST. So you can use your ST to surf the web with Lynx, read your mail with Mutt, and run all the Linux text based programms.

For using your atari ST as a Unix/Linux terminal you will need:

  • a serial port, or an USB to serial adapter on your Unix/Linux computer
  • a null modem cable to connect the serial port of the ST to the serial port of your Linux system.
  • an Atari ST or better with Terminal Emulator software. We recommend to use TAZ.

USB serial adapter on Linux

An USB serial adapter looks like this:
Usb serial.jpg

You can just throw the CD driver away, as Linux has built-in support for these devices. When plugged, you can see it has been recognized using the dmesg command.

[137052.801088] usb 5-1: new full speed USB device using uhci_hcd and address 7
[137053.000142] usb 5-1: New USB device found, idVendor=0403, idProduct=6001
[137053.000151] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[137053.000158] usb 5-1: Product: USB Serial Converter
[137053.000162] usb 5-1: Manufacturer: FTDI
[137053.000167] usb 5-1: SerialNumber: FTFNLXMS
[137053.000422] usb 5-1: configuration #1 chosen from 1 choice
[137053.008214] ftdi_sio 5-1:1.0: FTDI USB Serial Device converter detected
[137053.008277] usb 5-1: Detected FT232RL
[137053.008282] usb 5-1: Number of endpoints 2
[137053.008287] usb 5-1: Endpoint 1 MaxPacketSize 64
[137053.008292] usb 5-1: Endpoint 2 MaxPacketSize 64
[137053.008296] usb 5-1: Setting MaxPacketSize 64
[137053.009259] usb 5-1: FTDI USB Serial Device converter now attached to ttyUSB0 

Most important to us here is the last line, which tells that the kernel has assigned the name /dev/ttyUSB0 as a serial port.

Start a Linux login prompt on the serial port

Depending on the Linux distribution you use, you will have to configure it differently. On a Debian 6 (Squeeze system), which uses the sysvinit startup system, you have to edit the file /etc/inittab

Inside this file you should add a line like

T0:23:respawn:/sbin/getty -h -L ttyUSB0 19200 ansi

This means: start a login process on the serial line ttyUSB0, of speed 19200 bits/s, where a "ansi" text terminal will connect.

To assure this process is started, you have to restart the init process, with the command

telinit q

Make sure the process is really running with

pgrep -lf ttyUSB
21546 /sbin/getty -h -L ttyUSB0 19200 ansi

Of course if you enter ttyUSB0 it has to match the serial device detected by your system. If you plug and replug the usb serial adapter, it might appears as ttyUSB1 in that case of course the serial login won't work.

Start Taz on the Atari side and configure it

Just the usual GNU/Linux system in text mode

You can download TAZ from your favourite Atari archive:

It is also heavily recommended to HSMODEM program to your AUTO folder, which is a better serial port driver than the one included in TOS. Again HSMODEM shoud be available on your favourite Atari archive.

Inside Taz, you should configure the program to use a speed of 19200 bits/s, and use a Terminal type of ansi.

You can also download here a zip archive or disk image of all the files, ready to be unpacked on a floppy.

After starting Taz, press enter, and you should be greeted by the familiar Linux prompt.

If the screen displays garbage characters instead of a login prompt, just unplug and replug the usb serial adapter, and wait 5 seconds for getty to relaunch a terminal line. It might be also that the Linux side and the Atari side are using different speeds for the serial port communication.